The present invention, in some embodiments thereof, relates to Additive Manufacturing (AM) of an object, more particularly, but not exclusively, to a system and method for additive manufacturing of an object using a combination of materials and/or scanning patterns.
Additive manufacturing is generally a process in which a three-dimensional (3D) object is manufactured utilizing a computer model of the object. Such a process is used in various fields, such as design related fields for purposes of visualization, demonstration and mechanical prototyping, as well as for rapid manufacturing (RM).
The basic operation of any AM system consists of slicing a three-dimensional computer model into thin cross sections, translating the result into two-dimensional position data and feeding the data to control equipment which manufacture, in a layerwise manner, a three-dimensional structure on a working surface.
Additive manufacturing entails many different approaches to the method of fabrication, including three-dimensional printing, laminated object manufacturing, fused deposition modeling and others.
In three-dimensional printing processes, for example, a building material is dispensed from a dispensing head having a set of nozzles to deposit layers on a supporting structure. Depending on the building material, the layers may then be cured or solidified using a suitable device. The building material may include modeling material, which forms the object, and support material, which supports the object as it is being built. Various three-dimensional printing techniques exist and are disclosed in, e.g., U.S. Pat. Nos. 6,259,962, 6,569,373, 6,658,314, 6,850,334, 7,183,335 7,209,797, 7,225,045, 7,300,619, 7,479,510, 7,500,846, 7,658,976 and 7,962,237, and U.S. Published Application No. 20100191360, all of the same Assignee, the contents of which are hereby incorporated by reference.
AM facilitates rapid fabrication of functioning prototypes with minimal investment in tooling and labor. Such rapid prototyping shortens the product development cycle and improves the design process by providing rapid and effective feedback to the designer. AM can also be used for rapid fabrication of non-functional parts, e.g., for the purpose of assessing various aspects of a design such as aesthetics, fit, assembly and the like. Additionally, AM techniques have been proven to be useful in the fields of medicine, where expected outcomes are modeled prior to performing procedures. It is recognized that many other areas can benefit from rapid prototyping technology, including, without limitation, the fields of architecture, dentistry and plastic surgery where the visualization of a particular design and/or function is useful.
The deposition of materials according to two-dimensional position data to form a layer can generally be accomplished by establishing a relative lateral motion between the dispensing device (e.g., printing head, extrusion nozzle, etc.) and the working surface along some motion pattern. Known in the art are two types of motion patterns, referred to as “raster scan” and “vector scan.” Raster scan is characterized by a back and forward relative motion between the dispensing device and working surface, typically using several nozzles for parallel deposition. During the raster scan all the locations on the working surface are visited by the dispensing device, wherein a controller selectively activates and deactivates the dispensing nozzles for each visited location according to the two-dimensional position data. In vector scan, the dispensing device does not visit all the locations on the working surface. Instead, the relative motion is along a path selected based on the locations at which material deposition is required.
U.S. Pat. No. 6,193,923 to Leyden discloses a rapid prototyping technique in which a print head is displaced over a working surface in both a scanning direction and an index direction. Leyden teaches two scanning protocols. In one protocol a motion of the printing head in the main scanning direction is followed by a smaller increment of movement in a secondary scanning direction while no dispensing occurs, which in turn is followed by a reverse scan in the main scanning direction in which dispensing again occurs. In another protocol, the small secondary scanning movements are performed while main scanning occurs. Leyden also discloses vector scanning and a combination of vector scanning and raster scanning.
Several AM techniques allow additive formation of objects using more than one modeling material. For example, U.S. Published Application No. 20100191360 of the present Assignee, the contents of which are hereby incorporated by reference, discloses a system which comprises an additive manufacturing apparatus having a plurality of dispensing heads, a building material supply apparatus configured to supply a plurality of building materials to the fabrication apparatus, and a control unit configured for controlling the fabrication and supply apparatus. The system has several operation modes. In one mode, all dispensing heads operate during a single building scan cycle of the fabrication apparatus. In another mode, one or more of the dispensing heads is not operative during a single building scan cycle or part thereof.